Pipes in sprinkler systems are generally hung from an elevated or overhead support, such as a ceiling beam, by pipe hangers. A typical pipe hanger, shown suspending a pipe from a horizontal support in FIG. 1, includes a metal strap bent into a tear drop shape, having two ends which overlap. A pipe hanging rod extends through the overlapping ends to support the unit. The upper portion of the hanger is a yoke, while the lower portion is a saddle in which the liquid carrying pipe rests.
One type of bracket which has traditionally been used to suspend a hanging rod from the vertical surface of an overhead beam is made of solid steel, cast or bent into an L-shape. The bracket is typically quite heavy. One of the legs has an orifice at one end which receives a fastener that attaches the bracket to a support. When the bracket is mounted on the support, the other leg protrudes horizontally from the support. This horizontally extending leg is drilled and threaded to receive a threaded pipe hanging rod. Although the part exceeds the fire sprinkler industry standards for hanging four-inch pipe, the two-step process of drilling and tapping is expensive. This bracket is over-qualified for its intended purpose, making its added expense unnecessary.
Another type of bracket employed to suspend pipes from an overhead support is shown in FIG. 2. This second bracket is typically much lighter than the first bracket discussed above. Protruding from the vertical axis of the bracket are three semicircular holding bands. The top and bottom bands protrude in the same direction while the middle band protrudes in the opposite direction. Thus, the flat side of each band lies in one plane. Each of the three bands is stamped with threads. Extending from the plane which the three holding bands share, is an angled section which leads to a vertical mounting plate with an aperture for receiving a fastener for mounting the bracket to a wall. A hanging rod is threadedly inserted into the channel created by the three offset bands. For proper restraint within the channel, the rod is threadedly inserted until its end aligns with the top of the upper holding band.
This second bracket does not facilitate adjustment of the height at which the liquid carrying pipe is suspended by the hanger. The hanging rod must be inserted a minimum distance into the bracket for proper restraint. Additionally, the rod cannot extend much further than this minimum distance into the bracket due to the angled section which limits vertical motion of the hanging rod into the bracket. Thus, there is a very small range of heights at which a given hanging rod can suspend a pipe.
Additionally, the construction of this lightweight bracket does not compensate adequately for sideloading, or forces which act in a non-vertical direction, on the three holding bands. The three bands are connected to one another and to the mounting plate by only small connecting sections, making these areas susceptible to breakage. A sideload, or force pulling in a direction other than directly downward, can exert a strong force on this weak area of the bracket, thereby causing the bracket to break. Such a non-vertical force might occur, for example, in an earthquake.
Considering brackets used in industries other than fire sprinkler installation, U.S. Pat. No. 239,009 to Griffith discloses a bracket which is typically made of a rectangular strip of sheet metal. It is bent into a U-shape, having legs which touch one another along their length, such that a cylindrical channel is formed at the apex of the U-shape and a mounting section is formed by the adjoining legs of the U-shape. If it were threaded, the channel would be capable of accepting a bolt, but it could not dependably support a liquid carrying pipe since the channel is located to the side of the bracket mounting section.
U.S. Pat. Nos. 4,473,205 and 4,488,695, both issued to Rumble, disclose a pipe hanger wherein the ends of a strip of metal are stamped into semi-cylindrical sections with threads, and the strip is bent to form a saddle with the ends brought together to form a threaded bore for receiving a hanging rod. A separate fastener is needed to hold the threaded end sections of the metal strip together.
An improved side beam pipe hanging bracket is desired, and it is the object of the present invention to supply a lightweight, yet strong and easy to manufacture pipe hanging bracket.